Over the past three decades public transit bus systems have been losing market share of commuter trips to the private motor vehicle, which in turn contributes to traffic congestion, air pollution, and energy consumption in large urban areas.
In order to make bus service more efficient and attractive many cities have reserved the motor vehicle lane of a street adjacent to the pedestrian walk (sidewalk) exclusively for buses in an express bus system. This lane is often referred to as the curb lane, and is used as a bus priority lane in the morning and evening rush hours. During the remainder of the day, the lane may be open to all traffic or reserved as parking lane for private motor vehicles. However, this express bus system capacity and service is limited by the size of the bus vehicles which must still be able to navigate streets, the passenger boarding time, and the road traffic. That is to say, rapidity of bus service operating in exclusive lanes adjacent to the sidewalks is influenced by the length of the vehicle, the control of fare collection with respect to passengers boarding the system, as well as motor vehicle traffic lights and the need to negotiate left turn movements, all of which increases a bus patron's trip time often in crowded conditions.
Traditionally, higher capacity rapid transit has been served by urban rail systems separated from road traffic. These rail rapid transit lines, on routes from the suburbs to the downtown, need to be constructed in an existing railroad right-of-way, or on a wide street with a treed boulevard in the middle. Generally these rail lines need to be built on wide parcels of low-priced land often away from the households of regular public transit users. In the downtown, core the line is usually constructed underground as the public streets are occupied by motor vehicles and privately owned land is too expensive to acquire for an elevated track right-of-way and stations.
Highly used fixed bus routes are found on arterial streets in densely populated areas of the city where land is expensive. Therefore, there is a need to develop an efficient high capacity rapid bus system that can be built in a city street to replace a heavily used fixed route bus service operating in road traffic. This will be a useful tool for the urban transit industry to reduce traffic congestion on arterial streets, air pollution and energy consumption in populated urban centers by attracting commuters that will leave their private vehicles at home for work trips on a high capacity comfortable rapid bus service.
Attempts have been made to increase the capacity of public transit service running on city streets by increasing the frequency between vehicles and the size of the vehicles. In the past, when crowded streetcars were running bumper to bumper, usually in the downtown, a city had the customer base to justify building a subway system. The other option of replacing crowded bumper to bumper streetcars with elevated trains became problematic as access to the elevated station platforms required expensive private property and complex designs for the station house to control entry to the system as well as stairs, escalators, and handicap elevators to reach the train.
Applicant is aware of the following patents that are directed to devices and systems useful in mass transportation of people in cities.
U.S. Pat. No. 3,457,876 to Holden discloses a railway system in which the cars are suspended below an elevated rail or rails and lowered to ground level to unload and load passengers.
U.S. Pat. No. 3,861,315 to Rypinski discloses an elevated trackway and support structure along a railroad right of way with a traction system having cables that drop down to pick up vehicles such as a car, truck or bus, and elevates them into a train of vehicles for transport along the trackway.
U.S. Pat. No. 3,890,904 to Edwards discloses a railway system where the cars travel on rails mounted on the side of a support beam that has the trackway and cars in the same horizontal plane. The system further discloses a special station feature based on the provision of an elevator in the car.
U.S. Pat. No. 4,394,837 to Edwards discloses an elevated railway system (as noted in U.S. Pat. No. 3,890,904 above) with elevators at each of the doors of the rail car in the stationhouse permitting passengers on the ground level station platform egress and ingress to the rail car.
U.S. Pat. No. 4,690,064 to Owen discloses an elevated side-mounted monorail transportation system with a conventional station building having side platforms for passenger unloading and loading.
U.S. Pat. No. 5,372,072 to Hamy discloses a transportation system moving passengers along a guide beam in both the horizontal and vertical plane.
U.S. Pat. No. 5,456,183 to Geldbaugh discloses an elevated structural beam trackway incorporating a side mounted passenger vehicle for traveling along the median strip of existing expressway infrastructure above the roadway traffic with conventional stationhouse and station platforms.